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Image Processing

We are in the midst of a visually enchanting world, which manifests itself with a variety of forms and shapes, colors and textures, motion and tranquility. The human perception has the capability to acquire, integrate, and interpret all this abundant visual information around us. It is challenging to impart such capabilities to a machine in order to interpret the visual information embedded in still images, graphics, and video or moving images in our sensory world. It is thus important to...

The DWT implementation is basically frame-based as opposed to the DCT-type block-based implementation. Such an implementation requires both a large number of arithmetic computations and a large memory. Recently, a new mathematical formulation for wavelet transformation has been proposed by Swelden 11 based on spatial construction of the wavelets and a very versatile scheme for its factorization has been suggested in 12 . This new approach is called the lifting-based wavelet transform, or simply...

Currently text-based search engines are commercially available, and they are predominant in the World Wide Web for search and retrieval of information. However, demand for search and mining multimedia data based on its content description is growing. Search and retrieval of contents is no longer restricted to traditional database retrieval applications. As an example, it is often required to find a video clip of a certain event in a television studio. In the future the content customers will...

The baseline JPEG compression algorithm is widely used among the four modes in JPEG family. This is defined for compression of continuous-tone images with 1 to 4 components. Number of components for grayscale images is 1, whereas a color image can have up to four color components. The baseline JPEG allows only 8-bit samples within each component of the source image. An example of a four-component color image is a CMYK (Cyan, Magenta, Yellow, and Black) image, which is used in many applications...

The binarized signature image, as in Figure 12.3(a), is thinned using any standard thinning algorithm. The objective is to obtain a trajectory of the pen-tip. It may be observed from Figure 12.3(b) that the thinned image does not accurately capture the pen-tip trajectory, while it adequately preserves the structural information necessary for recognition. Some artifacts introduced by thinning are loops and holes in the binary image are reduced to single segments. strokes intersect on a sequence...

Bayesian decision theory is a very good tool for pattern classification. Assume that there are N classes of patterns C , C2, , Cjv, and an unknown pattern x in a d-dimensional feature space x x , x2, x , , x . Hence the pattern is characterized by d number of features. The problem of pattern classification is to compute the probability of belongingness of the pattern x to each class Ci, i 1,2, ,N. The pattern is classified to the class Cfc if probability of its belongingness to Cfc is maximum....

Fig. 5.2 2D Gabor filter (a) Real component, (b) Imaginary component. Fig. 5.2 2D Gabor filter (a) Real component, (b) Imaginary component. Each of the complex Gabor filters has the real (even) and imaginary (odd) parts that are conveniently implemented as the spatial mask of M x M sizes. For a symmetric region of support, M is preferred to be an odd number. A class of self-similar functions, referred to as Gabor wavelets, can be obtained by appropriate dilation and rotation of the mother Gabor...

The human eye does not respond to subtle differences in illumination. The purpose of contrast enhancement is to improve the overall visibility of the image gray levels. This may be achieved by transforming the image gray levels in such a way that the dark pixels appear darker and light pixels appear lighter. Such a transform increases the differences in gray level intensity and thus enables our vision system to discern these differences. The contrast stretching algorithms may employ...

Copyright 2005 by John Wiley &amp Sons, Inc. All rights reserved. Published by John Wiley &amp Sons, Inc., Hoboken, New Jersey. Published simultaneously in Canada. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the...

Fig. 12.4 Chest Image (a) Original, enhanced by (b) histogram equalization, (c) local area histogram equalization, (d) another input original image, (e) enhanced by contrast limited adaptive histogram equalization. Figure 12.4(a) is the original chest x-ray image. In Figure 12.4(b) and (c), the lung boundaries and edges of the bones are enhanced using histogram equalization and local area histogram equalization respectively. Figure 12.4(d) is another original chest x-ray image and the enhanced...

Although both RGB and CMYK color models are extremely useful for color representation, color processing, and also for development of hardware, these models are in no way similar to the human vision model. One of the major limitations of the RGB color space is that it is a nonuniform one. Uniform color space is one in which the Euclidean color distance between two color points at any part of the color space corresponds to the perceptual difference between the two colors by the human vision...

X-ray images on photographic films are the oldest and most frequently used form of medical imaging. X-ray imaging is the fastest and easiest way for a physician to view and assess broken bones, a cracked skull or in back bone. X-ray is useful in detecting more adverse forms of cancer in bones. Diagnostic X-ray images can be created by passing small highly controlled amounts of radiation through the body, capturing the resulting shadows and reflections on a photographic plate. The X - ray images...

Here w represents the convolution window. A simple 3x3 blurring functions may look like this There are conventional methods like inverse filtering, Wiener filtering, Kalman filtering, Algebraic approach, etc., to restore the original object. In all these cases we assume that the blurring function H is known. If H is known, then obviously we can get back or restore the original image f x,y , simply by convolving the degraded image with the inverse of the blurring function. To remove the noise,...

Application of image processing techniques in defense surveillance is an important area of study. There is a continuous need for monitoring the land and oceans using aerial surveillance techniques. Suppose we are interested in locating the types and formation of Naval vessels in an aerial image of ocean surface. The primary task here is to segment different objects in the water body part of the image. After extracting the segments, the parameters like area, location, perimeter, compactness,...

There is a growing demand of image processing in diverse application areas, such as multimedia computing, secured image data communication, biomedical imaging, biometrics, remote sensing, texture understanding, pattern recognition, content-based image retrieval, compression, and so on. As a result, it has become extremely important to provide a fresh look at the contents of an introductory book on image processing. We attempted to introduce some of these recent developments, while retaining the...